About greenfield disease
What is greenfield disease?
Metachromatic leukodystrophy, the most common form of leukodystrophy, is a rare inherited neurometabolic disorder affecting the white matter of the brain (leukoencephalopathy). It is characterized by the accumulation of a fatty substance known as sulfatide (a sphingolipid) in the brain and other areas of the body (i.e., liver, gall bladder, kidneys, and/or spleen). The fatty protective covering on the nerve fibers (myelin) is lost from areas of the central nervous system (CNS) due to the buildup of sulfatide. Symptoms of metachromatic leukodystrophy may include convulsions, seizures, personality changes, spasticity, progressive dementia, motor disturbances progressing to paralysis, and/or visual impairment leading to blindness.
Metachromatic leukodystrophy is inherited as an autosomal recessive trait. There are three forms of the disease that have similar symptoms. However, they are distinguished by the age of onset: infantile, juvenile, and adult forms of metachromatic leukodystrophy.
What are the symptoms for greenfield disease?
General symptoms of MLD that are seen in all three forms of the disease include:
- abnormal muscle movement
- behavior problems
- decreased mental function
- decreased muscle tone
- difficulty walking
- difficulty eating or feeding
- frequent falls
- a loss of muscle control
- problems with nerve function
- difficulty speaking
- difficulty swallowing
What are the causes for greenfield disease?
Metachromatic leukodystrophy is an inherited disorder caused by an abnormal (mutated) gene. The condition is inherited in an autosomal recessive pattern. The abnormal recessive gene is located on one of the nonsex chromosomes (autosomes). To inherit an autosomal recessive disorder, both parents must be carriers, but they do not typically show signs of the condition. The affected child inherits two copies of the abnormal gene — one from each parent.
The most common cause of metachromatic leukodystrophy is a mutation in the ARSA gene. This mutation results in a lack of the enzyme that breaks down lipids called sulfatides that build up in the myelin.
Rarely, metachromatic leukodystrophy is caused by a deficiency in another kind of protein (activator protein) that breaks down sulfatides. This is caused by a mutation in the PSAP gene.
The buildup of sulfatides is toxic, destroying the myelin-producing cells ― also called white matter ― that protect the nerves. This results in damage to the function of nerve cells in the brain, spinal cord and peripheral nerves.
What are the treatments for greenfield disease?
Metachromatic leukodystrophy can be managed with several treatment approaches:
- Medications. Medications may reduce signs and symptoms, such as behavioral problems, seizures, difficulty with sleeping, gastrointestinal issues, infection and pain.
- Physical, occupational and speech therapy. Physical therapy to promote muscle and joint flexibility and maintain range of motion may be helpful. Occupational and speech therapy can help maintain functioning.
- Nutritional assistance. Working with a nutrition specialist (dietitian) can help provide proper nutrition. Eventually, it may become difficult to swallow food or liquid. This may require assistive feeding devices as the condition progresses.
- Other treatments. Other treatments may be needed as the condition progresses. Examples include a wheelchair, walker or other assistive devices; mechanical ventilation to assist with breathing; treatments to prevent or address complications; and long-term care or hospitalization.
Care for metachromatic leukodystrophy can be complex and change over time. Regular follow-up appointments with a team of medical professionals experienced in managing this disorder may help prevent certain complications and link you with appropriate support at home, school or work.
Potential future treatments
Potential treatments for metachromatic leukodystrophy that are being studied include:
- Gene therapy and other types of cell therapy that introduce healthy genes to replace diseased ones
- Enzyme replacement or enhancement therapy to decrease buildup of fatty substances
- Substrate reduction therapy, which reduces the production of fatty substances
Coping and support
Caring for a child or family member with a chronic and progressively worsening disorder such as metachromatic leukodystrophy can be stressful and exhausting. The level of daily physical care increases as the disease progresses. You may not know what to expect, and you may worry about your ability to provide the care needed.
Consider these steps to prepare yourself:
- Learn about the disorder. Learn as much as you can about metachromatic leukodystrophy. Then you can make the best choices and be an advocate for yourself or your child.
- Find a team of trusted professionals. You'll need to make important decisions about care. Medical centers with specialty teams can offer you information about the disorder, coordinate your care among specialists, help you evaluate options and provide treatment.
- Seek out other families. Talking to people who are dealing with similar challenges can provide you with information and emotional support. Ask your doctor about support groups in your community. If a group isn't for you, maybe your doctor can put you in touch with a family who has dealt with the disorder. Or you may be able to find group or individual support online.
- Consider support for caregivers. Ask for or accept help in caring for your loved one when needed. Options for additional support can include asking about sources of respite care, asking for support from family and friends, and taking time for your own interests and activities. Counseling with a mental health professional may help with adjustment and coping.
What are the risk factors for greenfield disease?
Metachromatic leukodystrophy-MLD is also known as Greenfield’s disease. Metachromatic leukodystrophy is a lysosomal storage disease, wherein the myelin sheath that covers most of the nerve fibers of the central and peripheral nervous systems gets damaged.
1. The deficiency of the lysosomal enzyme arylsulfatase A - ARSA or its sphingolipid activator protein B -SapB results in MLD or greenfield disease.
2. Moreover, deficiency of the ARSA and SapB protein is caused by mutations in the ARSA and PSAP genes, respectively. Greenfield’s disease or MLD is an autosomal recessive lysosomal storage disease (OMIM:250100) caused by arylsulfatase.
3. The severity of metachromatic leukodystrophy is determined by the residual ARSA activity, depending on the type of mutation.
4. Without ARSA, sulfatides build up especially in the cells of the nervous system, causing damage to various organs like the kidneys and nervous system, including the brain and spinal cord.
5. The affected nerves in the body are damaged. MLD causes demyelination to occur hence they’re unable to send electrical impulses.
6. In addition, sulfatides cause the accumulation of calcium in the cell cytoplasm, which results in a change in calcium homeostasis, cell stress, and apoptosis.
Muscle weakness or lack of muscle control,Decreased nerve conduction,Spasms,Ataxia,Oculomotor paralysis,Bulbar palsy,Blindness,Deafness,Dementia,Developmental delays
Impaired motor function,Spastic tetraparesis,Ataxia,Spasms,Optic atrophy,Cognitive impairment
Treatment consists mainly of managing the symptoms,Promising results have been seen on treating gene therapy,Bone marrow transplantation delays the progression of the disease in some infantile-onset cases
Is there a cure/medications for greenfield disease?
Metachromatic leukodystrophy can't be cured yet, but clinical trials hold some promise for future treatment. Current treatment is aimed at preventing nerve damage, slowing progression of the disorder, preventing complications and providing supportive care. Early recognition and intervention may improve outcomes for some people with the disorder.
As the disorder progresses, the level of care required to meet daily needs increases. Your health care team will work with you to help manage signs and symptoms and try to improve quality of life. Talk to your doctor about the possibility of participating in a clinical trial.